5种湿地植物生理生长特性变化及其对污水净化效果的研究

Growth Characteristics and Sewage Cleaning Effect of Five Wetland Plants

为了研究湿地植物生理生长特性变化及其对生活污水的净化效果,选择芦苇、千屈菜、扁秆藨草、水葱和长苞香蒲5种湿地植物进行污水净化试验。通过测定植物生理生长参数和污水中CODCr、TP、NH+4-N的去除效果,评价湿地植物对污水的净化效果。结果表明:污水处理5种植物光合生理参数、Fv/Fm值、株高和生物量净增长高于清水培养,其中长苞香蒲、水葱和芦苇7月的净光合速率、Fv/Fm值及叶绿素含量均高于清水培养,且差异显著(P<0.05);5种湿地植物对污水中CODCr、TP和NH+4-N都具有良好的去除效果,各试验水体中CODCr浓度由192mg·L-1降至8～19mg·L-1,总磷浓度由1.46mg·L-1降至0.04～0.15mg·L-1,NH+4-N浓度由1.26mg·L-1降至0.01～0.1mg·L-1。研究得出,污水处理植物的生理生长特性优于清水培养植物,5种湿地植物对污水中CODCr、TP和NH+4-N去除效果明显;综合各参数来看,长苞香蒲、水葱和芦苇可作为人工湿地净化污水的优先选择,其次为千屈菜和扁秆藨草。

Five species of wetland plants, including Phragmites australis, Lythrum salicaria, Scirpus planiculmis, Scirpus validus and Typha angustata, were selected to grow in sewage. Their biological characteristices were assessed and their capability to remove nutrients, such as chemical oxygen demand （CODCr ）, total phosphorous（TP）and ammonia nitrogen（NH＋4-N）in constructed wetland systems, was analyzed. During the experimental period, the growth characteristices and sewage cleaning effect of each plant was evaluated by both physiological and chemical methods. The results demonstrated that the plants cultivated in sewage grew better than those in tap water as measured by plant photosynthesis, chlorophyll fluorescence, plant height, and biomass. There were significant differences between the plants growing in tap water and in sewage as measured by net photosynthetic rate, Fv/Fm, Chlorophyll content （P0.05）of Typha angustata, Scirpus validus and Phragmites australis（P0.05）. Furthermore, it was shown that all of the five species are highly efficient in removing CODCr 、TP and NH＋4-N, as the concentration of CODCr was decreased from 192 mg·L^-1 to 8～19 mg·L^-1 , TP from 1.46 mg·L^-1 to 0.04～0.15 mg·L^-1 , and NH＋4-N from 1.26 mg·L^-1 to 0.01～0.1 mg·L^-1 . We conclude that the five species grow better in the sewage than in the tap water. Typha angustata, Scirpus validus and Phragmites australis are the better ones among the five in remedying eutrophic water and improving water quality, fol- lowed by Lythrum salicaria and Scirpus planiculmis.